1. Field of the Invention
The present invention relates to a machine for separating a softer outer material from an inner harder material and particularly separating fish fillets from fish bone. More particularly the present invention relates to a machine using cutting blades canted inwardly to cut through the soft fish meat with the blades being guided by automatically actuated guide wheels coordinated with a conveyor carrying the fish body between the canted blades, the blade spacing being automatically varied to generally correspond to the thickness of the bone. More particularly the invention relates to a system and machine for filleting fish carried on an endless conveyor using preferably inwardly canted, scalloped band saw blades adjustably and automatically spaced by the machine.
2. Prior Art & General Background
Fish filleting machines of various types are known in the prior art. Operating ideally, these machines are designed to provide boneless, totally edible fillets from a fish processed by the machine.
Various fish filleting machines are known which use band saw blades in order to cut the fillets from the bone. Among these are U.S. Pat. Nos. 2,654,119 issued Oct. 6, 1953 to J. J. Duggan; 1,728,254 issued Sept. 17, 1929 to O. G. Rieske; 3,596,308 issued Aug. 3, 1971 to Leon S. Kenny et al; 1,759,828 issued May 27, 1930 to J. J. Barry; and 1,754,157 issued Apr. 8, 1930 to E. A. Gallison; among others.
______________________________________ U.S. Pat. No. Patentee(s) Issue Date ______________________________________ 1,552,463 J. J. Barry 09/08/25 1,757,013 E. A. Gallison 05/06/30 1,883,822 R. Reid et. al. 10/18/32 2,210,955 O. G. Rieske 08/13/40 ______________________________________
Filleting fish by machines as well as by hand present the problem of filleting a sufficient number of fish in a certain time period at an efficient cost.
One of the biggest problems with fish filleting machines of the prior art is that of leaving too much fish meat on the discarded central bone section. Several approaches have been taken to this problem, such as for example using blades with adjustable positions, however these have been largely inefficient requiring time to be set for each fish or requiring manual control with constant monitoring of the machine.
Various methods of attempting to avoid this include U.S. Pat. No. 3,596,308, which provided for cutting blades to be set to the approximate size of the fish, these blades being canted outwardly to steadily move out in response to the cant pressing through the fish. The fish was fed backwards, tail first, to so that the smallest diameter bone was presented to the blades first, which then steadily expanded out. This technique, however, may expand out from the bone too quickly and requires too much adjustment prior to feeding fish through the machine.
Another problem with automatic machines is the safe and effective feeding of the fish to be cut. Most mechanisms have used either rollers (note U.S. Pat. No. 3,596,308, for example), or carriages (note U.S. Pat. Nos. 1,754,157 and 2,654,119). These may require adjustment for even small changes in fish size and may require feeding the fish dangerously close to the cutting blades or possible misfeeds close to the cutting blades. The prior art also often required removal of the cut fish too dangerously close to the cutting process.
Additionally the prior art has largely ignored the specifies of the cutting blade, tending to ignore the benefits or drawbacks of specially designed cutting elements.
A further problem addressed by the present invention is keeping the cutting blades and cutting surface free of fish shavings which may foul the cutting process.
It is therefore an object of the invention to rapidly fillet fish, that is to separate the fish meat from the inner fish bone.
It is also an object of the invention to automatically fillet fish leaving less meat on the fish bones than heretofore achieved.
It is also an object of the invention to provide fish fillets for varying sizes of fish with a minimum amount of adjustment being necessary.
It is also an object of the invention to provide a method of filleting fish, which is largely free from fouling during the cutting process and is safe for the operators of the machine.
It is also an object of the invention to provide a fish filleting machine which is relatively compact and transportable, as well as of relatively high speed and through put.
It is also an object to provide a cutting blade selected for maximum efficiency with the present system.
Additional prior patents disclosing fish filleting machines which may be of interest are listed below:
3. General Discussion of the Invention
The present invention addresses these objects by providing a continuous filleting process capable of processing for example fifteen to sixteen fish per minute or possibly more. This rate is approximately ten times faster than the rate fish are processed by hand.
The present invention also addresses the problem of maximizing the amount of meat in the fillets from each fish by providing blades canted inwardly, rather than outwardly or parallel as suggested in the prior art. In this way, as the fish is fed through forwardly head first and tail last, the blades are farthest apart spaced at a distance of approximately the diameter or maximum thickness of the bone. However as the blades enter the fish, the inward cant with the resistance of the fish meat causes the blades to move inwardly until they reach the bone of the fish. The cant is not so great as to cut into the bone, however. It has been found that with the blades used at the speeds of processing used, an angle of two to three degrees for each blade from being parallel to each other is the optimum, any more causing the bone to be cut and any less not providing the automatic self-adjustment by the canted blade desired.
The invention is further automated by having the spacing of the cutting blades adjusted automatically so that, as larger fish are provided, the correction required for the canted blades is minimized.
Additionally, the invention provides for a safe conveyor or system which assures that the fish will be taken through the cutting system properly without undue monitoring by the operator.
This is done by providing a guide in which the fish is placed and over which the fish is conducted for cutting. The fish is placed between opened, vertical pins while on the guide a safe distance from the cutting blades and between opposed conveyor chains.
The pins then close automatically around the fish, holding the fish securely in place and centered for cutting, while toothed or pinned plates on the chains traveling on the chains grasp the fish. The teeth are pointed, but preferably without any hooks, to securely hold the fish without causing undue damage to the fish fillets. After the fish is removed by the pin means on the chains, the vertical pins which firmly held the fish centered, automatically open so that the next fish may be placed in the machine. This all takes place at a significant distance from the cutting blades which assures the safety of the operator.
The toothed plates and opposed chains provide sufficient gripping force to keep the fish from misfeeding, while holding the fish loosely enough to prevent compressing the fish against the cutting blades.
Additionally, the chains and plates serve to carry the fish safely past the cutting process, so that the fillets may be removed without the operator having to come close to the cutting process.
The plates may be made to continue to grip the fish fillets on either side of the bone as they circuit around the gears after the fillets have been cut away from the bone so that the bone is deposited where the chains move apart. The fish fillets are deposited in separate containers after being removed off the pins by scrapers located above the containers for the fillets.
The invention is contained in a frame of unitary construction for easy assembly, while also being compact.
The invention provides for maximum cutting efficiency by using a scallop based saw blade, of the type designed for cutting bread. Scallop blades avoid the problems of adjustment and waste due to the failure to follow the bone which were encountered with the teethed blades of the prior art. Scallop blades also avoid the problems of failing to follow the bone and of moving too slowly encountered with regular knife blades and navy blades.
The invention also provides for keeping the blades and cutting surface clean from cuttings by being equipped with a water spray over the cutting area and which may be turned on during the cutting process to wash both fish and cutting surfaces and saw blades for cleanliness and lubrication.